Battery housing and systems and methods of making thereof

ABSTRACT

A method of assembling a button cell battery. The method includes positioning a free end of a grommet over a free end of a top, and a free end of a can over a top panel of the grommet. The can includes a skirt having a vertical first section extending from a top panel of the can, and an outwardly tapered second section extending from the first section. An inner diameter of the skirt in the first section is substantially equal to an outer diameter of the top panel. The method also includes resizing a put-together arrangement defined following positioning the can over the grommet and positioning the grommet over the top from a first, expanded configuration to a second, constrained configuration, where an inner diameter of the skirt in the second section is substantially equal to the inner diameter of the skirt in the first section following resizing.

CROSS-REFERENCE TO RELATED PATENT APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.17/223,134, filed on Apr. 6, 2021, which claims the benefit of andpriority to U.S. Provisional Application No. 63/009,562, filed on Apr.14, 2020, the entire disclosures of which are hereby incorporated byreference herein.

FIELD

The present technology relates generally to batteries. More particularlythe technology relates to rechargeable button cell batteries.

BACKGROUND

The presence of entrapped gas within an assembled battery is undesirablefor a number of reasons. For example, contamination in and/or moisturecarried by trapped gas may cause unintended side reactions in the cell.Gas trapped within the battery interior also decreases the volumeavailable to accommodate evolved gasses, and increases the pressurewithin the battery interior, thus increasing the risk of leakage anddecreasing cell safety. Also, positive pressure (i.e. pressure in excessof ambient pressure) caused by trapped gas may interfere with theability to weld components to the battery housing, and thus may lead tomanufacturing inefficiencies. Given the sensitive chemistry ofrechargeable button cell batteries (as compared, e.g., to primary buttoncell batteries or larger cell batteries), the effects of entrapped gasmay be particularly undesirable during the assembly of rechargeablebutton cell batteries.

One option for mitigating problems associated with the entrapment of gaswithin the interior of a battery involves the assembly of a batterywithin an inert gas environment. By minimizing the risk of introducingcontaminants and moisture, this option reduces the occurrence of certainundesired consequences associated with trapped gas (e.g., unintendedside reactions in a cell). However, this option does not remedy theissues posed by the increased interior pressure within a batteryresulting from the entrapment of inert gas during the assembly of thebattery.

Another option for mitigating problems arising from the entrapment ofgas involves the creation of a vacuum within the battery housing duringthe assembly process. However, this process is difficult, and oftenunsuccessful. Furthermore, even when the battery interior issuccessfully subject to a vacuum, the negative pressure within thebattery interior (i.e. a pressure that is less than ambient pressure)may pose similar problems to those posed by the battery interior havinga positive pressure. For example, batteries having an interior subjectto a negative pressure may suffer from an increased risk of leakage, andthe negative pressure may interfere with the ability to weld componentsto the battery housing, etc.

SUMMARY

In one implementation of the present disclosure, a housing for a buttoncell battery includes a grommet and a can. The grommet has a top paneland a skirt. The can has a top panel and a skirt. The skirt of the canextends between the top panel and a free end, and includes (e.g., isdefined by) a substantially vertical first section and an outwardlytapered second section. The first section extends from the top panel ofthe can. The second section extends from the first section. A flow pathbetween an outer surface of the skirt of the grommet and an innersurface of the skirt of the can is defined upon assembly of the grommetwithin the can. The flow path extends between the second section and thefree end of the can. The flow path may be defined by a radial offset ofthe outer surface of the skirt from the inner surface of the skirt ofthe can.

The skirt of the can further optionally includes (e.g., is defined by)by an outwardly tapered third section that extends between the secondsection and the free end. The skirt of the can extends at a first anglerelative to an axis about which the can is centered in the secondsection and extends at a second angle relative to the axis in the thirdsection. The first angle is different than the second angle. Forexample, the first angle is greater than the second angle.

In some embodiments, the third section includes (e.g., is defined by) aplurality of different transition sections. Each transition section isdefined by a portion of the skirt that extends at an angle relative tothe axis that is different than an angle relative to the axis at whichan adjacent transition section extends. According to some embodiments,at least one of the transition sections is substantially vertical.

An inner diameter of the skirt of the can at the interface between thefirst section and second section is greater than an outer diameter ofthe top panel of the grommet. A skirt of the grommet is optionallyoutwardly tapered.

In one implementation of the present disclosure, can for a button cellbattery include a top panel and a skirt. The skirt extends between afirst end located adjacent the top panel and a free second end. Theskirt includes (e.g., is defined by) a first section extending from thefirst end, a second section extending from the second end, and a thirdsection extending between the first section and second section. Thefirst section has a substantially uniform inner diameter. The secondsection extends at a first angle relative to an axis about which the canis centered. The third section extends at a second angle relative to theaxis that is different than the first angle.

In some embodiments, a height of the can, as measured along the axis, isbetween approximately 3.6 mm and approximately 6.0 mm. An interfacebetween the first section and second section may be locatedapproximately 0.05 mm and approximately 0.40 mm from a lower surface ofthe top panel. An interface between the second section and the thirdsection is optionally located approximately 0.40 mm and approximately0.80 mm from a lower surface of the top panel. According to some suchembodiments, the can may be a component of a housing for a size 10, 13,size 312 or size 675 hearing-aid battery. According to otherembodiments, the can may be a component of a housing for any other sizebattery, and may thus be defined having any other range of differentheights.

The third section optionally includes (e.g., is defined by) a pluralityof different transition sections. Each transition section is defined bya portion of the skirt that extends at an angle relative to the axisthat is different than an angle relative to the axis at which anadjacent transition section extends. In some embodiments, at least onetransition section is substantially vertical.

According to one implementation of the present disclosure, a method ofassembling a button cell battery is described. A free end of a grommetis positioned over a free end of a top. A free end of a can ispositioned over a top panel of the grommet. The can includes a skirthaving a substantially vertical first section that extends from a toppanel of the can, and an outwardly tapered second section that extendsfrom the first section. An inner diameter of the skirt in the firstsection is substantially equal to an outer diameter of the top panel ofthe grommet.

A put-together arrangement defined following the positioning of the canover the grommet and the positioning of the grommet over the top isresized from a first, expanded configuration to a second, constrainedconfiguration. Following the resizing of the put-together arrangement,an inner diameter of the skirt of the can in the second section issubstantially equal to the inner diameter of the skirt in the firstsection.

In some embodiments, the resizing of the put-together arrangementincludes supporting a top panel on the top on a platform provided at acenter of a cylinder of a resize press. A free end of the can issupported on a base of a track formed along the upper surface of thecylinder. The base is vertically offset from the upper surface of thecylinder. The resize die of the resize press is lowered onto theput-together arrangement until a lower surface of the resize diecontacts the upper surface of the cylinder.

Upon the lower surface of the resize die contacting the upper surface ofthe cylinder, a lower portion of the put-together arrangement is notcontained within a bore defined by the resize die. The lower portion ofthe put-together arrangement is introduced into an interior of a bore ofa constraining die. The bore has a tapered diameter that decreases insize between a first diameter defined at an open end of the bore and asecond diameter defined within the interior of the bore. The firstdiameter of the bore is greater than a diameter of the lower portion ofthe put-together arrangement. The free end of the can is optionallysealed relative to the top panel of the top. The free end of the grommetis optionally sealed along the top panel of the top. The grommet extendsbetween, and insulates, the can from the top. In some embodiments, anelectrode tab electrically coupled to an electrode assembly positionedwithin the top may be laser welded to an inner surface of the canfollowing the sealing of the free end of the can relative to the toppanel of the top. The foregoing summary is illustrative only and is notintended to be in any way limiting. In addition to the illustrativeaspects, embodiments and features described above, further aspects,embodiments and features will become apparent by reference to thefollowing drawings and the detailed description.

DESCRIPTION OF DRAWINGS

FIG. 1 illustrates a perspective, partial sectional view of an assembledbutton cell battery, according to one embodiment.

FIG. 2 is a diagram representative of a put-together phase in theassembly of a button cell battery.

FIG. 3 illustrates a can, the enlarged portion of FIG. 3 providing adetailed view of the transition between the accommodation section,expanded section and main body section of the can, according to oneembodiment.

FIG. 4A illustrates a partial cross-sectional view of a put-togetherarrangement of a can and grommet, according to one embodiment.

FIG. 4B illustrates a partial cross-sectional view of a put-togetherarrangement of a can, grommet and top, according to one embodiment.

FIG. 5 illustrates a can, the enlarged portion of FIG. 5 providing adetailed view of the transition between the accommodation section,expanded section and main body section of the can, according to oneembodiment.

FIGS. 6-8 illustrate a can, according to various embodiments.

FIGS. 9A and 9B illustrate a grommet, according to one embodiment.

FIG. 10 illustrates a grommet, according to one embodiment.

FIGS. 11-14 representatively depict a method of assembling aput-together arrangement of a battery into an assembled battery,according to one embodiment, wherein FIG. 11 illustrates a resize pressaccording to one embodiment, the enlarged portion of FIG. 11 providing adetailed view of the resize press; FIG. 12 illustrates a pre-crimppress, according to one embodiment, the enlarged portion of FIG. 12providing a detailed view of the pre-crimp press; FIG. 13 illustrates acrimp press, according to one embodiment, the enlarged portion of FIG.13 providing a detailed view of the crimp press; and FIG. 14 illustratesan eject press, according to one embodiment.

DESCRIPTION

Various embodiments are described hereinafter. It should be noted thatthe specific embodiments are not intended as an exhaustive descriptionor as a limitation to the broader aspects discussed herein. One aspectdescribed in conjunction with a particular embodiment is not necessarilylimited to that embodiment and may be practiced with any otherembodiment(s).

Referring to FIG. 1 , a partial sectional view of an assembled buttoncell battery 10 is shown according to one representative embodiment. Thebattery 10 generally comprises a can 100, a grommet 200, a top 300, andan electrode assembly 400. The can 100, grommet 200, and top 300 eachinclude (e.g., are defined by) a top panel 101, 201, and 301,respectively, as well as a skirt 103, 203, and 303, respectively.

As shown in FIG. 1 , in the assembled configuration of the battery 10,the can 100, grommet 200, and top 300 define a sealed housing having acavity within which the electrode assembly 400 is contained. Theelectrode assembly 400 is electrically coupled to the housing such thatthe top 300 and the can 100 each form one pole (e.g. anode or cathode)of the battery 10. For example, the top panel 201 of the grommet 200 isoptionally provided with an opening 207 (e.g., a central hole) via whicha weld tab or other structure (not shown) extends to electrically coupleone of the anode and cathode of the electrode assembly 400 to an innersurface of the can 100 (e.g., a lower surface of the top panel 101).Alternatively, other structures and/or electrode configurations may beused to electrically couple the anode and cathode of the electrodeassembly 400 to one of the top 300 and can 100.

During an initial phase of the assembly of the battery 10, the top 300is inverted (i.e., positioned such that the top panel 301 of the top 300is located below the skirt 303), and the electrode assembly 400 ispositioned within a cavity defined by the top 300. One or moreadditional processes related to the incorporation of the electrodeassembly 400 with the top 300 (e.g., the welding of an electrode tab toan interior surface of the top 300, filling the cavity of the top 300with electrolyte solution, etc.) may optionally also be performed duringthe initial assembly phase.

As representatively illustrated by the arrows in the diagram of FIG. 2 ,during a put-together phase in the assembly of the battery 10, the freeend 105 of the can 100 is placed over the top panel 201 of the grommet200. The grommet 200 and the can 100 are then moved relative to oneanother until the grommet 200 has been received within the can 100 (suchas, e.g., representatively shown in FIG. 4B). This nested arrangement ofthe can 100, grommet 200, top 300 and electrode assembly 400 formed uponcompletion of the put-together assembly phase defines a put-togetherarrangement of the battery 10.

Following the put-together assembly phase, the free end 105 of the can100—and optionally the free end 205 of the grommet 200 is sealed (e.g.,crimped) relative to the top panel 301 of the top 300 to define a sealedarrangement of the battery 10. The sealed battery 10 is then optionallysubject to one or additional processes (e.g. the laser welding of anelectrode tab to an interior surface of the can 100) to finalize theassembly of the battery 10.

Referring generally to FIGS. 3-10 , can and grommet features that definea flow path via which gas may escape during the assembly of a batteryare shown and described according to various embodiments. As discussedin more detail below, the can and grommet features, according to any ofthe embodiments described herein, advantageously minimize (e.g. prevent)the entrapment of gas and resultant increased pressure within theinterior of an assembled battery. Not only are the can and grommetfeatures described herein advantageously able to achieve a neutralpressure (i.e. a pressure substantially equal to ambient pressure duringassembly of the battery) within the interior of the assembled battery,but they are able to do so without relying on the application of avacuum to the interior of the battery during assembly.

Turning to FIG. 3 , a can 100 having a flow path-defining configurationis shown according to one example embodiment. As representativelyillustrated by the can 100 of FIG. 3 , the flow path-defining can 100configuration generally includes an skirt 103 having an accommodationsection 110 that axially aligns the can 100 and grommet 200 relative toone another, and an expanded section 120 and main body section 130 thatradially offset the skirt 103 of the can 100 from the skirt 203 of thegrommet 200 to provide a continuous flow path 50 (see FIGS. 4A and 4B)via which gas may escape during the assembly of the put-togetherarrangement.

As shown in FIG. 3 , the portion of the skirt 103 of the can 100defining the accommodation section 110 extends substantiallyperpendicular (i.e. extends substantially vertically) relative to thetop panel 101 of the can 100, and has a substantially uniform diameteralong its height. An inner diameter of the portion of the skirt 103defining the accommodation section 110 is dimensioned substantiallyequal to the outer diameter of the top panel 201 of the grommet 200.This dimensioning of the accommodation section 110 relative to thegrommet 200 helps align a central axis of the grommet 200 with a centralaxis of the can 100 during the arrangement of the grommet 200 within thecan 100. By thus facilitating a centered arrangement of the grommet 200and can 100, the accommodation section 110 advantageously minimizes therisk of a non-symmetrical arrangement of the grommet 200 and can 100that could compromise the ability of the can 100 and top 300 to besealingly closed during subsequent stages in the assembly of the battery10. Given the pliable (e.g., elastomeric) construction of the grommet200, the accommodation section 110 may optionally be formed having aninner diameter that is equal to, or less than, the outer diameter of thetop panel 201 of the grommet 200 (i.e., such that the grommet 200 isradially compressed as it is inserted into the can 100), thereby furtherreducing the risk of a non-centered arrangement of the grommet 200 andcan 100.

The height of the accommodation section 110 may vary according todifferent embodiments. In general, the height of the accommodationsection 110 is selected to be sufficiently large, so as to achieve adesired centering of the grommet 200 and can 100 relative to oneanother. However, it may also be desirable to limit the height of theaccommodation section 110, so as to minimize a distance between theexpanded section 120 and the top panel 101 of the can 100. Notably,locating the expanded section 120 closer to the top panel 101 mayincrease the degree to which a flow path 50 defined between the can 100and grommet 200 extends relative to a height of the can 100 as thegrommet 200 is arranged within the can 100. The increased length of theflow path 50 provided by minimizing a height of the accommodationsection 110 (and thereby locating the expanded section 120 closer to thetop panel 101) may advantageously minimize the risk of gas beingentrapped within the put-together arrangement during the put-togetherphase in the assembly of the battery 10.

According to various embodiments, the accommodation section 110 may bedefined having a height of between approximately 0.05 mm andapproximately 0.50 mm, more particularly between approximately 0.01 mmand approximately 0.40 mm, and more particularly approximately between0.20 mm and approximately 0.30 mm. In various embodiments, the battery10 may be a size 13 or a size 312 hearing-aid battery. In suchembodiments, the accommodation section 110 may be defined having aninner diameter of between approximately 7.00 mm and approximately 8.00mm, more particularly between approximately 7.30 mm and 7.70 mm, andmore particularly between approximately 7.50 mm and approximately 7.60mm. According to other embodiments, the battery 10 may be a size 10hearing-aid battery. In such embodiments, the accommodation section 110may be defined having an inner diameter of between approximately 5.00 mmand approximately 6.00 mm, more particularly between approximately 5.20mm and 5.80 mm, and more particularly between approximately 5.40 mm andapproximately 5.50 mm. In yet other embodiments, the battery 10 may be asize 675 hearing-aid battery. In such embodiments, the accommodationsection 110 may be defined having an inner diameter of betweenapproximately 10.80 mm and approximately 11.80 mm, more particularlybetween approximately 11.00 mm and 11.60 mm, and more particularlybetween approximately 11.20 mm and approximately 11.30 mm. According toyet other embodiments, the battery 10 may be any other type of battery,and the diameter of the accommodation section 110 may be defined havingany range of different widths.

As shown in FIG. 3 , the expanded section 120 is defined by a portionthe skirt 103 of the can 100 that extends between the accommodationsection 110 and the main body section 130. The portion of the skirt 103defining the expanded section 120 increases in diameter in a directionbetween a first end 121 of the expanded section 120 (defined at theinterface between the expanded section 120 and the accommodation section110) and a second end 123 of the expanded section 120 (defined at theinterface between the expanded section 120 and the main body section130).

The first end 121 of the expanded section 120 has a diameter equal tothe diameter of the accommodation section 110. The second end 123 of theexpanded section 120 is defined by an inner diameter that is greaterthan an outer diameter of the top panel 201 of the grommet 200. As shownin FIGS. 4A and 4B, the relatively larger inner diameter of skirt 103defined at the second end 123 (as compared to the outer dimeter of thetop panel 201 of the grommet 200) provides a radial offset between anexterior surface of the grommet 200 and the interior surface of the can100 via which trapped gas may escape even as the top panel 201 of thegrommet 200 nears the top panel 101 of the can 100 during thearrangement of the grommet 200 within the can 100.

The expanded section 120 may be defined by a range of heights anddegrees of tapering. In general, increasing the degree of taperingdefining the expanded section 120, and maximizing the inner diameter ofthe second end 123 of the expanded section 120 may each help minimizethe risk of entrapping gas during the put-together assembly phase.Notably, minimizing the height of the expanded section 120 of the can100 results in the second end 123 of the expanded section 120 of the can100 being located closer to the top panel 101 of the can 100, which inturn allows the expanded section 120 to provide a radial offset betweenthe grommet 200 and can 100 even as the top panel 201 of the grommet 200nears the top panel 101 of the can 100. Meanwhile, maximizing the innerdiameter of the second end 123 of the expanded section 120 increases theradial offset between the inner surface 103 b of the skirt 103 of thecan 100 and the outer surface 203 a of the skirt 203 of the grommet 200as the grommet 200 is inserted into the can 100, and therebyadvantageously minimizes the risk of an obstruction to the egress of gasfrom the interior of the put-together arrangement.

However, increasing the degree of outward tapering of the expandedsection 120 may increase stress and strain on the can 100 during theresizing phase in the assembly of the battery 10 (described in moredetail with reference to FIG. 11 below), and thus may increase the riskof deformation of the can 100 during the assembly of the battery 10.Minimizing a height of the expanded section 120 may similarly lead to anincrease in the risk of deformation of the can 100, as reducing theheight of the expanded section 120 requires a corresponding increase inthe degree of outward tapering to provide a second end 123 defined by apredetermined, desired inner diameter. Thus, decreasing the height ofthe expanded section 120 may similarly lead to an increase in the riskof deformation of the can 100 during subsequent steps in the assembly ofthe battery 10. Accordingly, the selection of the height and the degreeof tapering that define the expanded section 120 may also vary based onconsiderations such as, e.g., the materials used for the construction ofthe can 100, the chemical sensitivity of the electrode assembly 400, thetypes of additional assembly phases to which the put-togetherarrangement may be subject (e.g., welding, etc.), etc.

According to some embodiments, the height of the expanded section 120may be between approximately 0.1 mm and approximately 1.0 mm, moreparticularly between approximately 0.15 mm and approximately 0.8 mm, andmore particularly between approximately 0.2 mm and approximately 0.6 mm.A degree of tapering of the expanded section 120 may be defined by anangle of between approximately 0 degrees and approximately 25 degrees,more particularly between approximately 5 degrees and approximately 15degrees, and more particularly between approximately 9 degrees andapproximately 13 degrees. For example, according to one exampleembodiment, the expanded section 120 has a height of 0.25 mm and has adegree of tapering of 13 degrees. According to another exampleembodiment, the expanded section 120 has a height of 0.51 mm and has adegree of tapering of 9 degrees. In yet another example embodiment,expanded section 120 has a height of 0.51 mm and has a degree oftapering of 11 degrees.

Referring again to FIG. 3 , the portion of the skirt 103 of the can 100that defines main body section 130 corresponds to a portion of the skirt103 extending between the expanded section 120 and the free end 105 ofthe can 100. The main body section 130 is defined along its height byone or more transition portions 131. Each transition portion 131 isdefined by a height and a degree of tapering (i.e. angle at which thetransition portion 131 extends relative to the central axis of the can100). An inner diameter of a transition portion 131 may be constant(i.e., may define a vertical transition portion 131 a), or may varyalong the height of the transition portion 131 (i.e., may define anoutwardly tapered transition portion 131 b). As illustrated by thevarious can 100 embodiments shown in FIGS. 3-8 , the number oftransition portion(s) 131 that define the main body section 130 as wellas the heights and degree of tapering defining each of the transitionportion(s) 131 of the main body section 130 may vary according todifferent embodiments.

The heights and degrees of tapering defining each of the one or moretransition portions 131 are selected such that the main body section 130is able to provide a continuous, radial offset between the inner surface103 b of the skirt 103 of the can 100 and the outer surface 203 a of theskirt 203 of the grommet 200 as the grommet 200 is positioned within thecan 100. Accordingly, an inner diameter of the free end 105 of the can100 is greater than a largest outer diameter of the grommet 200.

The configuration of the expanded section 120 and main body section 130(i.e., the number of transition portions 131 defining the main bodysection 130, the height and degree of tapering defining the transitionportions 131 and expanded section 120, etc.) may be based on theconfiguration of the exterior of the skirt 203 of the grommet 200. Forexample, in embodiments in which the grommet 200 comprises asubstantially vertical skirt 203, the main body section 130 mayoptionally comprise a single transition portion 131 that is asubstantially vertical transition portion 131 a, such as, e.g.,representatively illustrated by the can 100 of FIG. 5 . In otherembodiments, the grommet 200 may be outwardly tapered (e.g., tofacilitate the placement of the grommet 200 onto the top). Accordingly,as illustrated in FIGS. 3-4B and 6-8 , the main body section 130 mayoptionally also comprise one or more tapered transition portions 131 bthat are optionally separated by vertical transition portions 131 a.

In addition to, or as an alternative to, the flow path-defining canfeatures described with respect to FIGS. 3-8 , the grommet 200 mayoptionally also be defined by flow path-defining features via which gasmay escape during assembly of the battery 10. For example, asrepresentatively illustrated by FIGS. 9A-10 , one or morediscontinuities 220 may be formed along the annularly extending wallthat defines skirt 203 of the grommet 200. During the insertion of thegrommet 200 into the can 100, the discontinuities 220 along the skirt203 of the grommet 200 define channels between the outer surface 203 aof the grommet 200 and the inner surface 103 b of the skirt 103 of thecan 100 that provide a flow path 50 via which gas may escape.

As representatively illustrated by the triangle-shaped segment 211 cutfrom the skirt 203 of the grommet 200 embodiment of FIGS. 9A and 9B, thediscontinuities 220 are optionally defined along the lower edge 209 ofthe grommet 200. The discontinuities 220 may optionally also be formedalong a portion of the annular wall defining the skirt 203, such as,e.g., the holes 213 formed through the skirt 203 of the grommet 200embodiment of FIG. 10 . Although the discontinuities 220 of the grommet200 embodiments of FIGS. 9A-10 are shown as extending entirely throughthe skirt 203 (i.e. the discontinuities 220 are formed through each ofthe inner surface 203 b and outer surface 203 a of the skirt 203), thediscontinuities 220 may alternatively be formed along only an outersurface 203 a of the skirt 203 of the grommet 200 (e.g., thediscontinuities 220 may be defined by debossed portions of the outersurface 203 a of the skirt 203 of the grommet 200).

Referring to FIGS. 11-14 , a system for, and method of, finalizing theassembly a of a put-together arrangement having a can 100 comprisingflow path-defining features as described according to any embodimentherein into an assembled battery 10 (such as representativelyillustrated by FIG. 1 ), is described according to one exampleembodiment. In general, the system includes a resize press 500 (see,e.g., FIG. 11 ), a pre-crimp press 600 (see, e.g., FIG. 12 ), a crimppress 700 (see, e.g., FIG. 13 ), and an eject press (see, e.g., FIG. 14).

Referring to FIG. 11 , the resize press 500 includes a cylinder 501(e.g., a metal cylinder) having a flat upper surface 502. A stepped,grooved track 503 is formed in (e.g., defined by) the upper surface 502.The track 503 extends circumferentially about a central axis of thecylinder 501. As shown in FIG. 11 , the track 503 includes a depressed,flat base 504 that is vertically offset from the flat upper surface 502.An outer vertical wall 505 (e.g., a step formed in the upper surface502) connects the flat base 504 of the groove and the upper surface 502of the cylinder 501.

A platform 506 is located within, and extends upwards relative to, aninner perimeter of the track 503. As representatively illustrated inFIG. 11 , the platform 506 is optionally defined by an upper surface ofa pin 507 (e.g., a non-conductive pin) that is supported within anopening 508 formed through a center of the upper surface 502. An outersurface of the pin 507 defines an inner vertical wall that extendsbetween the flat base 504 of the track 503 and the platform 506.Alternatively, the platform 506 is defined by the upper surface 502 ofthe cylinder 501, with the inner vertical wall being defined by a stepformed in the upper surface 502 at a location surrounding an innerperimeter of the track 503.

During the resize phase of the assembly of the battery 10, the invertedtop 300 of the put-together arrangement of the battery 10 is placed ontothe platform 506. As shown in FIG. 11 , the free end 105 of the can 100(and optionally the free end 205 of the grommet 200) extends past thetop panel 301 of the inverted top 300, and is supported by the base 504of the track 503. Once the put-together arrangement of the battery 10has been positioned relative to the platform 506 and track 503, a resizedie 510 supported by an upper portion of the resize press 500 is loweredonto the put-together arrangement of the battery 10.

The resize die 510 defines a bore 509 having a diameter that correspondsto the desired final diameter of the assembled battery 10. Thus, as theresize die 510 is moved along the exterior of the put-togetherarrangement of the battery 10 in a downward direction, the resize die510 compresses the outwardly tapered, enlarged diameter of the main bodysection 130 of the can 100 into a substantially vertical, resizedconfiguration. As the resize die 510 is moved downwards relative to theput-together arrangement of the battery 10, the flow path 50 definedbetween the can 100 and grommet 200 advantageously facilitates theescape of air out from between the free ends 105, 205 of the can 100 andgrommet 200, respectively.

During the resize phase, the outer vertical wall 505 prevents the freeends 105, 205 of the can 100 and grommet 200 from flaring outwards inresponse to the compressive force imparted by the downwards movement ofthe resize die 510 over the put-together arrangement. The resize die 510is lowered relative to the put-together arrangement until a lowersurface of the resize die 510 contacts the upper surface 502 of thecylinder 501. Because downwards movement of the resize die 510terminates upon a lower surface of the resize die 510 reaching the uppersurface 502 of the cylinder 501, the resize die 510 does not pass overthe lower, expanded portions of the can 100 and grommet 200 that extendbetween the upper surface 502 of the cylinder 501 and the flat base 504of the track 503. Accordingly, the lower expanded portions of the can100 and grommet 200 are not resized into a reduced-diameterconfiguration during the resize phase.

During an initial stage of the pre-crimp phase, the lower, un-resizedexpanded portions of the can 100 and grommet 200 adjacent the free ends105, 205 of the can 100 and grommet 200, respectively, are resized tomatch a diameter of the previously resized portion of the battery 10(i.e., the lower expanded portions are resized to a dimension similar tothe desired diameter of the assembled battery 10). During a secondarystage of the pre-crimp phase, the free ends 105, 205 of the can 100 andgrommet 200, respectively, are curled inwards relative to the top panel301 of the top 300.

As shown in FIG. 12 , the resizing of the lower, un-resized expandedportions of the can 100 and grommet 200 during the pre-crimp phase isperformed using a constraining die 601 of the pre-crimp press 600. Theconstraining die 601 includes a bore 602 that tapers inwardly from anenlarged first diameter 603 defined at an upper, open end of the bore602 to a reduced-size second diameter 604. The enlarged first diameter603 is dimensioned to accommodate the lower, un-resized expandedportions of grommet 200 and can 100. The diameter of the reduced-sizesecond diameter 604 corresponds to the desired final diameter of theassembled battery 10.

Following the resize phase, the lower, un-resized portion of the battery10 is positioned within and pushed into the open, upper end 603 of theconstraining die 601 until it is received within the portion of the bore602 defining the second diameter 604. The pre-crimp press 600 continuespushing the battery 10 through the constraining die 601 until the freeends 105, 205 of the can 100 and grommet 200, respectively, are broughtinto contact with an inwardly tapered surface 606 of a curling tool 605.This contact with the curling tool 605 causes the free ends 105, 205 ofthe can 100 and grommet 200, respectively, to be partially curledinwardly over the top panel 301 of the top 300. As the pre-crimp press600 pushes the free ends 105, 205 into contact with the tapered surface606 of the curling tool 605, the bore 602 of the constraining die 601constrains the battery 10, so as to prevent the outer diameter of thebattery 10 from being deformed (e.g., enlarged). Thus, the arrangementof the battery 10 defined upon completion of the pre-crimp phase has agenerally uniform, vertical diameter.

As shown in FIG. 0.13 , the constraining die 601 (and the curledarrangement of the battery 10 received therein) is transferred to thecrimp press 700 from the pre-crimp press 600 at the start of thecrimping step. The free end 105 of the can 100 (and optionally the freeend 205 of the grommet 200) is then pushed through the constraining die601 against an upper surface 702 of the crimp press 700, thereby sealingthe free ends 105, 205 relative to the top panel 301 of the top 300 todefine a crimped, assembled arrangement of the button cell battery 10.The crimped, assembled arrangement of the button cell battery 10continues to be pushed through the constraining die 601 until a desiredheight of the crimped, assembled arrangement of the button cell battery10 is achieved.

From the crimp press 700, the constraining die 601 (and crimped,assembled arrangement of the button cell battery 10 received therein) ismoved to the ejection press 800. At the ejection press 800, theconstraining die 601 is pushed against an eject die 801, therebyreleasing the assembled button cell battery 10.

Upon being ejected, the assembled button cell battery 10 may be subjectto any number of additional optional steps to finalize the manufactureof the battery 10. For example, an electrode tab coupled to one of theanode and cathode of the electrode assembly 400 may be welded to aninner surface of the can 100 of the assembled battery 10. For example,in one example embodiment, a cathode tab that is coupled at a first endto a cathode layer of the electrode assembly 400, and which extendsthrough the opening 207 of the grommet 200, is laser welded at itssecond end to a lower surface of the top panel 101 of the can 100.

As described above, the flow path 50-defining can 100 and/or grommet 200used to form the assembled battery 10 described herein minimizes (e.g.,prevent) the entrapment of gases within a cavity of the battery 10, suchthat the cavity of the battery 10 is advantageously subject to a neutralpressure (e.g. ambient pressure) following assembly. The welding of atab to a closed battery 10 that is subject to a neutral interiorpressure is more effective than the welding of a tab to a closed battery10 that is subject to either a negative interior pressure (which mayresult in a melt pool occurring during welding being sucked into thebattery 10) or a positive interior pressure (which may result in a meltpool occurring during welding being expelled from the battery 10).Accordingly, by improving the success rate of welding (e.g., laserwelding) an electrode tab to an interior of the assembled battery 10,the systems and methods described herein advantageously increase theefficiency of the manufacture of button cell batteries 10.

As used herein, the terms “about” and “approximately” will be understoodby persons of ordinary skill in the art and will vary to some extentdepending upon the context in which they is used. If there are uses ofthese teens which are not clear to persons of ordinary skill in the art,given the context in which it is used, “about” and “approximately” willmean up to plus or minus 10% of the particular term.

The use of the terms “a” and “an” and “the” and similar referents in thecontext of describing the elements (especially in the context of thefollowing claims) are to be construed to cover both the singular and theplural, unless otherwise indicated herein or clearly contradicted bycontext. Recitation of ranges of values herein are merely intended toserve as a shorthand method of referring individually to each separatevalue falling within the range, unless otherwise indicated herein, andeach separate value is incorporated into the specification as if it wereindividually recited herein. All methods described herein may beperformed in any suitable order unless otherwise indicated herein orotherwise clearly contradicted by context. The use of any and allexamples, or exemplary language (e.g., “such as”) provided herein, isintended merely to better illuminate the embodiments and does not pose alimitation on the scope of the claims unless otherwise stated. Nolanguage in the specification should be construed as indicating anynon-claimed element as essential.

While certain embodiments have been illustrated and described, it shouldbe understood that changes and modifications may be made therein inaccordance with ordinary skill in the art without departing from thetechnology in its broader aspects as defined in the following claims.

The embodiments, illustratively described herein, may suitably bepracticed in the absence of any element or elements, limitation orlimitations, not specifically disclosed herein. Thus, for example, theterms “comprising,” “including,” “containing,” etc. shall be readexpansively and without limitation. Additionally, the terms andexpressions employed herein have been used as terms of description andnot of limitation, and there is no intention in the use of such termsand expressions of excluding any equivalents of the features shown anddescribed or portions thereof, but it is recognized that variousmodifications are possible within the scope of the claimed technology.Additionally, the phrase “consisting essentially of” will be understoodto include those elements specifically recited and those additionalelements that do not materially affect the basic and novelcharacteristics of the claimed technology. The phrase “consisting of”excludes any element not specified.

The present disclosure is not to be limited in terms of the particularembodiments described in this application. Many modifications andvariations may be made without departing from its spirit and scope, aswill be apparent to those skilled in the art. Functionally equivalentmethods and compositions within the scope of the disclosure, in additionto those enumerated herein, will be apparent to those skilled in the artfrom the foregoing descriptions. Such modifications and variations areintended to fall within the scope of the appended claims. The presentdisclosure is to be limited only by the terms of the appended claims,along with the full scope of equivalents to which such claims areentitled. It is to be understood that this disclosure is not limited toparticular methods, reagents, compounds compositions, or biologicalsystems, which can of course vary. It is also to be understood that theterminology used herein is for the purpose of describing particularembodiments only and is not intended to be limiting.

In addition, where features or aspects of the disclosure are describedin terms of Markush groups, those skilled in the art will recognize thatthe disclosure is also thereby described in terms of any individualmember or subgroup of members of the Markush group.

As will be understood by one skilled in the art, for any and allpurposes, particularly in terms of providing a written description, allranges disclosed herein also encompass any and all possible subrangesand combinations of subranges thereof. Any listed range may be easilyrecognized as sufficiently describing and enabling the same range beingbroken down into at least equal halves, thirds, quarters, fifths,tenths, etc. As a non-limiting example, each range discussed herein maybe readily broken down into a lower third, middle third and upper third,etc. As will also be understood by one skilled in the art all languagesuch as “up to,” “at least,” “greater than,” “less than,” and the like,include the number recited and refer to ranges which may be subsequentlybroken down into subranges as discussed above. Finally, as will beunderstood by one skilled in the art, a range includes each individualmember.

Other embodiments are set forth in the following claims.

What is claimed is:
 1. A method of assembling a button cell battery, themethod comprising: positioning a free end of a grommet over a free endof a top; positioning a free end of a can over a top panel of thegrommet, the can comprising a skirt including: a substantially verticalfirst section extending from a top panel of the can; and an outwardlytapered second section extending from the first section; wherein aninner diameter of the skirt in the first section is substantially equalto an outer diameter of the top panel of the grommet; and resizing aput-together arrangement defined following the positioning of the canover the grommet and the positioning of the grommet over the top from afirst, expanded configuration to a second, constrained configuration;wherein an inner diameter of the skirt of the can in the second sectionis substantially equal to the inner diameter of the skirt in the firstsection following the resizing of the put-together arrangement.
 2. Themethod claim 1, wherein resizing the put-together arrangement comprises:supporting a top panel of the top on a platform provided at a center ofa cylinder of a resize press; supporting a free end of the can on a baseof a track formed along an upper surface of the cylinder, the base beingvertically offset from the upper surface of the cylinder; and lowering aresize die of the resize press onto the put-together arrangement until alower surface of the resize die contacts the upper surface of thecylinder.
 3. The method of claim 2, wherein a lower portion of theput-together arrangement is not contained within a bore defined by theresize die upon the lower surface of the resize die contacting the uppersurface of the cylinder.
 4. The method of claim 3, further comprisingintroducing the lower portion of the put-together arrangement into aninterior of a bore of a constraining die, the bore having a tapereddiameter that decreases in size between a first diameter defined at anopen end of the bore and a second diameter defined within the interiorof the bore; and wherein the first diameter of the bore is greater thana diameter of the lower portion of the put-together arrangement.
 5. Themethod of claim 4, further comprising sealing the free end of the canrelative to the top panel of the top.
 6. The method of claim 5, furthercomprising laser welding an electrode tab coupled to an electrodeassembly to an inner surface of the can following the sealing of thefree end of the can relative to the top, wherein the electrode assemblyis positioned within and electrically coupled to the top.
 7. A can for abutton cell battery, the can comprising: a top panel; and a skirtextending between a first end located adjacent the top panel and a freesecond end; wherein the skirt includes: a first section extending fromthe first end, the first section having a substantially uniform innerdiameter; a second section extending from the second end, the secondsection extending at a first angle relative to an axis about which thecan is centered; and a third section extending between the first sectionand second section, the third section extending at a second anglerelative to the axis that is different than the first angle.
 8. The canof claim 7, wherein a height of the can, as measured along the axis, isbetween approximately 3.6 mm and approximately 6.0 mm.
 9. The can ofclaim 8, wherein an interface between the first section and secondsection is located approximately 0.05 mm and approximately 0.40 mm froma lower surface of the top panel.
 10. The can of claim 8, wherein aninterface between the second section and the third section is locatedapproximately 0.40 mm and approximately 0.80 mm from a lower surface ofthe top panel.
 11. The can of claim 7, wherein the third section isdefined by a plurality of different transition sections, each transitionsection being defined by a portion of the skirt that extends at an anglerelative to the axis that is different than an angle relative to theaxis at which an adjacent transition section extends.
 12. The can ofclaim 11, wherein at least one transition section is substantiallyvertical.
 13. A can for a button cell battery, the can comprising: a toppanel; and a skirt extending between a first end located adjacent thetop panel and a second end; wherein the skirt includes: a first sectionextending from the first end; a second section extending from the secondend, the second section extending at a first angle relative to an axisabout which the can is centered; and a third section extending betweenthe first section and second section, the third section extending at asecond angle relative to the axis that is different than the firstangle.
 14. The can of claim 13, wherein an interface between the firstsection and the second section is located approximately 0.05 mm andapproximately 0.50 mm from a lower surface of the top panel.
 15. The canof claim 13, wherein the first section has an inner diameter betweenapproximately 7.00 mm and approximately 8.00 mm.
 16. The can of claim13, wherein an interface between the second section and the thirdsection is located approximately 0.1 mm and approximately 1.0 mm from alower surface of the top panel.
 17. The can of claim 13, wherein thesecond angle is between approximately 0 degrees and approximately 25degrees relative to the axis.
 18. The can of claim 13, wherein the thirdsection has a height between approximately 0.20 mm and approximately0.30 mm, and wherein the second angle is between approximately 10degrees and approximately 15 degrees.
 19. The can of claim 13, whereinthe third section has a height between approximately 0.40 mm andapproximately 0.60 mm, and wherein the second angle is betweenapproximately 8 degrees and approximately 12 degrees.
 20. The can ofclaim 13, wherein the third section is defined by a single transitionportion that is substantially vertical relative to a lower surface ofthe top panel.